West Nile virus (WNV) is the leading cause of autochthonous arboviral disease in the United States. The virus is primarily spread to people through the bite of infected Culex species of mosquitos. WNV was first identified in Harris County, Texas, in 20022. Since then, the mosquito-borne virus has become endemic in the region, with surges in 2012 and 2014. Although majority of individuals infected are asymptomatic, WNV induced neuroinvasive infections often result in hospitalizations and adverse outcomes3-7, thus may pose a significant concern in public health and healthcare. The Harris County Public Health (HCPH) Surveillance and Epidemiology Unit (SEU) conducts surveillance of WNV in humans, in collaboration with Mosquito and Vector Control Division (MVCD) that monitors the virus in mosquito populations and birds. Mosquito abatement activities are implemented in areas where positive mosquitoes and human cases are identified. In this integrated model, clusters of WNV positive mosquito pools in relation with human cases provide comprehensive surveillance data to guide targeted efforts of mosquito control, disease prevention, and community education.
Objective: This abstract aims to: 1) describe human WNV infections in Harris County excluding the City of Houston, Texas, 2003 to 2018; 2) explore geographical distributions of WNV positive mosquito pools in relation to human cases; 3) provide a brief overview of the county's rigorous multidisciplinary WNV surveillance and control in mosquitoes and humans.